Position selecting motor control system



Aug. 30, 1949. R. G. MELROSE POSITION SELECTING MOTOR CONTROL SYSTEM 3Sheets-Sheet 1 Filed Feb. 15, 1945 INVEN T012. Faber) G. flip/rode m m mT A 1949- R. G. MELROSE 2,480,334

POSITION SELECTING MOTOR CONTROL SYSTEM Filed Feb. 15, 1945 3Sheets-Sheet 2 Aug- 1949- R. G. MELROSE 80,334

POSITION SELECTING MOTOR CONTROL SYSTEM Filed Feb. 15, 1945 3Sheets-Sheet 3 IN VEN TOR.

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ATTORNEK Patented Aug. 30, 1949 POSITION SELECTING MOTOR CONTROL SYSTEMRobert G. Melrose, Centerport, N. Y assignor to Republic AviationCorporation, Farmingdale, N. Y., a corporation of Delaware ApplicationFebruary 15, 1945, Serial No. 578,016

3 Claims.

This invention relates to controls for regulatin the operation ofmovable parts or elements and proposes predetermining the degree ofmovement of the controlled part by and from a set-. ting of the presentcontrol.

While the present invention is of general use and application wherevermovable members are to be adjusted, it is especially designed for use inconjunction with certain movable parts or elements of aircraft, such ascool-er doors or flaps (cowl, dive or landing gear), etc., usuallyoperated by electric motor drives, whereby the pilot may select, by andwith the present control, the desired adjusted position for thecontrolled element or member and is thereafter relieved of anysupervision of the control, or of the element to be adjusted, with theassurance that when the controlled element attains the adjusted positionpredetermined and selected by the control, its further movement isautomatically arrested.

With the above and other objects in view, as will be apparent, thisinvention consists in the construction, combination and arrangement ofparts all as hereinafter more fully described, claimed and illustratedin the accompanying drawings, wherein- Fig. 1 is an elevation of thepresent control 11.- lustrating the parts thereof in their respectiveneutral positions: 4'

Fig. 2 is a side elevation thereof:

Fig. 3 is a view similar to Fig. 1 disclosing a setting of the controllever away from its neutral position as shown in Fig. 1 and illustratesthe relationship of the components of the control at the time of theadjustment of the control lever an p i t a y adjusting movement of hecontrolled member or element:

Fig, 4 is a section taken through the control along line 4-4 of Fig. 3:

Fig. 5 is a View similar to Fig. 3 illustrating the relationship of thecomponents of the control at the completion of the adjusting movement ofthe controlled element or member corresponding to the setting of thecontrol lever shown in Fi 3:

Fig. 6 is a section taken along line lie- 6 of Fig. 5 to illustrate onetype of switch which may be employed in conjunction with the presentinvention for controlling the operation of the motor moving the elementor member to be adjusted; and

Fig. 7 is a schematic diagram illustrating the present inventionassociated with a movable control surface of an aircraft.

In aircraft structures there are certain elements or pa s, s ch a oilcoole d o s, cowl flaps, dive flaps, landing gear flaps, etc., which areconstantly being adjusted durin flight and which are usually moved foradjustment purposes by electric motor drives. Heretofore the pilot hasbeen compelled to manually regulate or control the operation of themotor moving the element or member being adjusted, and at the same timeobserve an indicator responsive to the movement of the adjusted elementor member which shows the several positions attained by the member orelement in its movement or adjustment. When the indicator discloses thatthe part or element being adjusted has attained or arrived at thedesired position the pilot releases the switch controlling the operationof the motor and stops its operation. This requires more or lessconstant attention to the adjustment and the control thereof by thepilot which in itself is undesirable and objectionable.

The present invention proposes making this adjustment automatic upon andby the predetermining and seleotlon of the adjusted position by thepilot, and after such position of adjustment has. been attained by themovable part or member, to automatically arrest the adjusting movementthereof. To that end a selector control is Dmvided by which the pilotmay select any position within the range of possible adjustment desiredfor the controlled part or member, whereupon the motor controlling thesame becomes instantly and automatically effective and remains eifectiveuntil the part reaches the selected or predetermined adjusted position,when the operation of the motor is automatically arrested. In thismanner the pilot once having selected the adjusted position for thecontrolled part or memher is relieved of further attention to thecontrol or the part or member to be adjusted.

Reference being had more particularly to the drawings, [0 designates afixed or stationary frame or quadrant secured to and spaced from acompanion frame or plate H) which in turn is fixedly secured to a partII of the aircraft structure. This quadrant l0 carries a scale l2 whichcoacts with the control lever IS, in a manner to be hereinafter morefully described, to predetermine or select the adjusted position of thecontrolled door or aircraft element, A pivot pin I3 is positionedbetween the quadrant I0 and the plate [0' and cooperates with themounting bolts [4, to mount and Support the quadrant l0 and the plate [0on the structure ll. Spacers I4" are mounted on the pin l3 and bolts Mto maintain the quadrant l 0 spaced from the plate l0 and/or thestructure ll. Suitable fastening means, such as the nuts I3'I4', operateon the pin 13 and the bolts I4 not only to secure the quadrant I53 andthe plate I 9 together, but also to mount the entire assembly upon thefixed part if of the aircraft structure. For this latter purpose thenuts or fastening means I3'-I4, may be removed so that the projectingends of the bolts I3-I4 may pass through corresponding apertures in thestructural part I I of the aircraft after which the nuts I3-I4 may bereplaced thereby effectively mounting the device as a unit. It is'to beunderstood however that this mounting of the device is a matter ofmechanical expediency and may be widely varied without in any wayeffecting this invention or its operation. In fact, if desired, theplate It) may be entirely eliminated and the instant device mounteddirectly upon the structural part II of the aircraft, in which event thestructure II performs all of the functions of the plate I and thequadrant I Q is supported in spaced relation thereto by the spacers orsleeves I4".

A control lever is pivotally mounted upon the pin I3 and in swingingthereon may move from one end of the scale I2 to the opposite endthereof. This lever I5 has a control plate I6, of gen erally triangularshape, secured thereto or formed integrally therewith, with its baseparallel to the scale I2 and its apex adjoining the pivot pin I3. Thepins I2 and spacers It" contact with the lever I5 at the limits of itspath of movement and thereby define such path which is substantiallycoextensive with the scale l2. The lever I5 carries an indicator orpointer I! which cooperates with or overrides the scale I2 to indicatethereon the position occupied by the lever as well as the positionpredetermined or selected for the controlled part or member upon itsadjustment.

A follower plate I8 is mounted for pivotal movement on the pin I3 to therear of the con trol plate I6 of the lever I5 and this follower plate I8is also substantially triangular in shape with its apex pivoted on thepin I3. The base or widest edge of the follower I8 substantiallycoincides with that of the control plate I6 but is longer than thelatter. It is to be noted that the follower plate I8 has generally agreater width than the control pltae I6 and that its side edge portionstherefore will project beyond the corresponding edges of plate I6 whenthe centers of both plates coincide as shown in Figs. 1 and 5. Thepivotal movement of the follower plate I8 on the pivot pin I3 is limitedby appropriate stops I9 fixed to the aircraft structure II or to theplate I0 at the extremities of the path of movement proposed for thefollower I8. I

The upper edge of the follower plate is grooved, as at 20, for thereception of the cord or cable 2I. At one of its ends the cord or cable2| is secured, as at 22, in one extremity of the groove while its bodyis seated in the groove 20 and passes along the edge of the followerplate I8 to extend to and be secured to the movable controlled part ormember. A coil spring 23 encircles the pivot pin I3 and is secured atone of its ends to the follower plate l8 and at its opposite end to theplate Ill or in the alternative of the structure II if the plate II) isomitted from the assembly. As the follower plate I8 moves in onedirection, for example to the right in Figs. 1, 3 and 5, under thecontrol of the cable 2!, it becomes increasingly spring loaded, andreversely when the tension on it is relaxed or is removed of the motormoving the controlled element or Adjacent each side of the followerplate I8 an electrical switch 2 2, such as illustrated in detail in Fig.6, is mounted to be controlled by a roller 25. This roller 25 isnormally projected into the path of movement of the controlled plate I6by any suitable means, for example by the spring 26 of the switch or bya leaf spring 27 carrying the roller 25 or by both of them. In anyevent, the position of the roller 25 determines the closing and openingof the switch 24 and its position in turn, is controlled by the plateI6. When the roller 25 is free of contact with the control plate it itsswitch 24 is open, but when the roller 25 is in contact with or isoverridden by the control plate If it is forced inwardly of the followerplate I8 against the forces or springs normally projecting it in theopposite direction or outwardly of the follower, and in being so forcedinwardly of the follower I8 closes the switch 24 and the circuitincluding it, thereby initiating the operation of the electric motoroperating the controlled element or member. The switch 24 will remainclosed and the motor will continue to operate so long as the controlplate It contacts with or overrides one or the other of the rollers 25.

The assembled control as above described, consists of this control leverI5 and plate I6 which is freely movable on the pivot pin I3 and in beingso moved can be positioned at any point on the scale I2 corresponding tothe position to which the part or member under adjustable control is tobe moved. This movement of the lever I5 and plate I6 is not transmittedto the follower I8 but does cause the plate I5 to override one or theother of the rollers 25 dependent upon the direction in which the leverI5 is swung, thereby closing its coacting switch 24 that in turn closesthe circuit of the motor causing it to rotate and move the part ormember to be adjusted. The adjusing movement of this part or memberresults in the movement of the follower I8, either by the spring 23 orby the cable 2I, until the previously depressed roller 25 rides free ofthe then stationary control plate It whereupon the roller 25 movesoutwardly of the follower l8 breaking the circuit by means of which theoperation of the motor is controlled.

The motor moving the controlled member or element is reversible so thatits operation in either direction will move the element or membercorrespondingly. Two switches 24 are provided, one at each edge of thefollower I8 and the closing of one of these switches causes the motor tooperate in one direction while the alternate closing of the other switchresults in the reverse operation of the motor. By the presentconstruction only three operative conditions are possible, to wit: bothswitches 24 open, or one switch open while the other is closed, orreversely the switch previously closed is open and that previously openis closed. These conditions result from the relative positions of theplates I6 and I8 and that is initially determined by the position of thelever I5 relative to the scale I2.

The connections between the switches 24 and the motor follows standardtechnique. For that tween and out of contact with the rollers 25 of theswitches 2% carried by the follower plate l8. When the elements are sosituated the circuits, including the switches 24 for the control of themotor are open and the controlled part or member is stationary. Themovement of the control .lever Hi to any adjusted position on, eitherside of on the scale l2, as for instance to the position shown in Fig.3, causes the control plate 16 thereof to ride over one or the other ofthe rollers 25 (in Fig. 3 shown as the roller 25 of the switch 24 to theleft) closing its coacting switch 24. This closes one of the circuitscontrolling the operation of the motor setting the latter in motion tomove the controlled member or element, the movement of which in turncauses the follower plate iii to move in the direction of the setting ofthe lever l5 under the impetus of the spring 23, or, in the alternative,under the control of the cable 2 I. In Fig. 3 this movement of thefollower !8 is by virtue of the force exerted thereon by the spring 23.The follower plate |8 continues its movement until the roller 25 carriedthereby, which has been previously depressed by the control plate 16, asillustrated in Fig. 3, passes beyond the edge of the control plate l6 asshown in Fig. 5, whereupon such depressed roller 25 moves outwardly ofthe follower I'B opening the cooperating switch 24 and breaking thecircuit, whereupon the operation of the motor and movement of thecontrolled part or member ceases, as does also the pivotal movement ofthe follower IS. A reverse movement on the part of the lever l5 causesthe reverse operation of the motor to place the cable 2| under tensionand move the follower l8 against the action of the spring 23 in theopposite direction.

In short, the movement of the lever |5 from any position where thecenters of the plates M5 and I8 coincide, and with both switches 24open, as

illustrated in Figs. 1 and 5, closes one or the other of the switches 24thereby energizing the motor and initiating the movement of thcontrolled member or element. This movement of the controlled element ormember causes the follower l8 to swing in one direction or the otherupon the pin |3 which movement continues until the relative positions ofthe plates I6 and i8 as illustrated in Figs. 1 and 5 are attained,whereupon the closed switch 24 opens and the entire movement isarrested.

The wiring, the structure controlled by the instant invention, the motorand the construction per se of the switches 24 respectively form no parthereof and therefore are not illustrated and described in detail.However, Fig. 7 schematically illustrates the instant invention incombination with a movable control surface 29 of an aircraft. In thisparticular example, the movable control surface 29 is fixedly mounted ona shaft 30 and is rotated through a predetermined arc, concentric tothat shaft, by means of a worm gear train 3| and a reversible electricmotor 32. A bellcrank or horn 33 is fixedly mounted on the controlsurface 29 and the cable 2| has one end thereof fastened to thebellcrank 33, while its other end is attached to the follower plate [8as above described. The switches 24 control the operation of the motor32 in either direction so that upon the closing of one of the switches24 the motor 32 rotates the control surface 29. The resultingdisplacement of the bellcrank 33 either places the cable 2| undertension, thereby rotating the follower plate |8 in a clockwisedirection, or relieves the static tension in the cable 2| to permit thespring 23 to rotate the follower plate IS in a counterclockwisedirection. In either case, as the control surface 29 reaches theposition predetermined by the adjustment of the lever Hi, the followerplate i8 moves into parallel alignment or coincidence with the controlplate |i and the actuated switch 24 opens, thereby arresting operationof the motor 32, and the rotation of the control surface 29. While thepresent invention has been described in conjunction with a movable partor element of an aircraft and in conjunction with electrical operatingdrives, it is of course manifest that it can be employed for selectingor predetermining the position to which any movable member is to beadjusted by any adaptable power means, regulated and controlled by anysuitable device as a substitute for the switches 24, all withoutdeparting from the spirit and scope hereof.

What is claimed is:

1. In a selector control for predetermining the adjustment of a movablemember the combination with a pair of parallel plates, each plate be inga sector of a disc and both plates being mounted adjacent one to theother for independent movement on a common pivot, one thereof beingwider to extend beyond the limits of the other when their respectivecenter lines coincide, of means for moving the narrower of said platesin either direction to a predetermined adjusted position thereby causingit to overlap one of the edge portions of the wider plate, a reversiblemotor for actuating the movable member in either direction, means formoving the wider plate from and in unison with the movement of themember being adjusted, and means carried by the edge portions of thewider of said plates to be actuated by the narrower plate whenoverlapping one or the other of the edge portions of the wider plate forcontrolling the operation of the motor to initiate the movement of themember being adjusted.

2. A selector control assembly for the adjustment on a common pivot,each of said plates beparallel plates mounted for independent movementon a common pivot, each of said plates being the sector of a disc andone of said plates being smaller than the other and constituting anadjustable control plate and the larger of said plates constituting afollower, said plates being organized and arranged so that the centersthereof coincide when the assembly is inoperative with the edge portionsof the follower projecting beyond the limits of the control plate, amotor for the operation and adjustment of the movable member, aconnection between the follower and the movable member under adjustmentwhereby the follower moves independently of the control plate and inunison with said member, and means carried on the edge portions of thefollower plate projecting beyond the limits of the control plate whenthe device is inactive to be actuated by the control plate on itsmovement out of coincidence with the follower, in either direction, forinitiating the operation of the motor and the adjustment of the movablemember.

3. A selector control for the adjustment of a movable member comprisinga control plate and a follower plate each plate being the sector of adisc and both plates being mounted in spaced parallel relationship andfor independent movement on a common pivot, the follower plate beingwider than the control plate to have the marginal edge portions thereofnormally extending beyond the limits of the control plate when thecenter lines of the plates coincide, a reversible motor for theoperation and adjustment of the movable member, a switch carried on eachmarginal portion of the follower plate, said switches respectivelycontrolling the actuation of the motor in opposite directions for thecorresponding adjustment of the movable member, a lever car ried by saidcontrol plate for displacing it out of its normal position to therebyproject it over one or the other of the marginal portions of thefollower plate to operate the switch carried by 8 such marginal portionof the follower plate, a cable directly connecting the follower plateand the member under adjustment whereby the follower plate is moved inone direction in unison with the member under adjustment until thenormal relative positions of the plates is resumed, and a springinterposed between the follower plate and its pivot to move the followerplate in the opposite direction in unison with the movable member as thecable connecting the movable member and the follower plate is relaxed bythe adjustment of the movable member and until the normal relativepositions is resumed.

ROBERT G. MELROSE.

REFERENCES CITED UNITED STATES PATENTS Name Date Reeves Aug. 8, 1944Number

